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Birth Season (birth + season)
Selected AbstractsEffect of seasonal programming on fetal development and longevity: Links with environmental temperatureAMERICAN JOURNAL OF HUMAN BIOLOGY, Issue 2 2009Andreas D. Flouris This study examined the effect of birth season on fetal development and longevity using two independent databases of all Greek citizens that were born (total: 516,874) or died (total: 554,101) between 1999 and 2003. We found significantly increased birth weight, gestational age, and longevity in individuals born during the autumn and winter seasons of the year. These individuals also demonstrated statistically significantly lower prevalence rates for fetal growth restriction and premature birth. Furthermore, we found that increased temperature at birth was associated with adverse effects on fetal development and longevity. In conclusion, our results show strong effects of season of birth on fetal development and longevity mediated, at least in part, by environmental temperature at time of birth. Am. J. Hum. Biol., 2009. © 2008 Wiley-Liss, Inc. [source] Strong association between birth month and reproductive performance of Vietnamese womenAMERICAN JOURNAL OF HUMAN BIOLOGY, Issue 1 2009Susanne Huber Epidemiological studies on premodern and modern Western societies indicate that birth season may influence female reproduction. Nothing is known, however, about this effect in developing economies. Many of the latter are characterised by tropical climates with a rainy season associated with lower food availability and a greater prevalence of infectious diseases. We therefore predict that an association between birth month and reproductive output, if it exists, should be related to the rainy season. To test this prediction, we analysed census data of Vietnam obtained from IPUMS-International (Vietnam 1999 Population and Housing Census). Based on 493,853 women born between 1950 and 1977 and thus aged 22 to 49 years, we found that the time series of mean offspring count per month of birth has a highly significant period of 12 months (power = 46.871, P < 0.00001). Our results further indicate that the 12-month periodic signal has a maximum in July and a minimum in January. Accordingly, the peak corresponds to birth during the rainy season, the low if the third pregnancy month concurs with the rainy season. The month of birth is therefore clearly associated with the later reproductive performance of Vietnamese women, strongly supporting the assumption that environmental and maternal conditions during early development exert long-term effects on reproductive functioning. Provided the rainy season adversely affects developmental processes due to inadequate food and/or high infection risk, the association reported here points to a critical period of reproductive development during early pregnancy. Am. J. Hum. Biol., 2009. © 2008 Wiley-Liss, Inc. [source] Season of birth contributes to variation in university examination outcomesAMERICAN JOURNAL OF HUMAN BIOLOGY, Issue 5 2006Martin Fieder Epidemiological studies show that birth season influences a wide range of biological parameters such as growth, reproduction, mental illnesses, dyslexia, personality, and success in school. The present study is aimed at examining birth season's relationship to examination marks achieved at a university in a very large contemporary sample of male and female undergraduate students. We find that female university students born in spring and summer achieve better marks than those born in autumn and winter. Male students born in spring receive worse marks than those born in other seasons of the year. Furthermore, we find a birth-week periodicity in examination results of female students, with highest examination results for those born in May. We suppose that biological mechanisms might explain part of the observed effects. Am. J. Hum. Biol. 18:714,717, 2006. © 2006 Wiley-Liss, Inc. [source] Risk Exposure in Early Life and Mortality at Older Ages: Evidence from Union Army VeteransPOPULATION AND DEVELOPMENT REVIEW, Issue 2 2009Dejun Su This study examines the relation between risk exposures in early life and hazard of mortality among 11,978 Union Army veterans aged 50 and over in 1900. Veterans' risk exposures prior to enlistment,as approximated by birth season, country of birth, residential region, city size, and height at enlistment,significantly influenced their chance of survival after 1900. These effects are robust irrespective of whether socioeconomic well-being in 1900 has been taken into account; however, they are sensitive to the particular age periods selected for survival analysis. Whereas some of the effects such as being born in Ireland and coming from large cities became apparent in the first decade after 1900 and then dissipated over time, the effects of birth season, being born in Germany, residential region in the United States, and height at enlistment were more salient in the post-1910 periods. Height at enlistment shows a positive association with risk of mortality in the post-1910 periods. Compared to corresponding findings from more recent cohorts, the exceptional robustness of the effects of risk exposures prior to enlistment on old-age mortality among the veterans highlights the harshness of living conditions early in their lives. [source] Effects of reproductive condition and dominance rank on cortisol responsiveness to stress in free-ranging female rhesus macaquesAMERICAN JOURNAL OF PRIMATOLOGY, Issue 7 2010Christy L. Hoffman Abstract The hypothalamic,pituitary,adrenal (HPA) axis modulates individuals' physiological responses to social stress, which is an inevitable aspect of the daily lives of group-living animals. Previous nonhuman primate studies have reported that sex, age, rank, and reproductive condition influence cortisol levels under stressful conditions. In this study we investigated cortisol responses to stress among 70 multiparous, free-ranging female rhesus macaques (Macaca mulatta) on the island of Cayo Santiago, PR. Plasma cortisol samples were collected in two consecutive years under similar conditions. Twenty-two females were sampled both years, and most of those females were lactating in only one of the years. Individual differences in cortisol levels were stable across years, even though reproductive condition changed for most individuals. No relationship was found between age or social rank and cortisol levels. Of the females that changed reproductive conditions, cortisol levels were higher when they were lactating than when they were cycling, and the amount of change in cortisol from cycling to lactating was greatest for low-ranking individuals. Heightened reactivity to stress during lactation may be the result of concerns about infant safety, and such concerns may be higher among low-ranking mothers than among higher ranking mothers. Psychosocial stress and hyperactivation of the HPA axis during lactation can suppress immune function and increase vulnerability to infectious diseases, thus explaining why adult females in the free-ranging rhesus macaque population on Cayo Santiago have a higher probability of mortality during the birth season than during the mating season. Am. J. Primatol. 72:559,565, 2010. © 2009 Wiley-Liss, Inc. [source] Seasonal birth patterns in myositis subgroups suggest an etiologic role of early environmental exposuresARTHRITIS & RHEUMATISM, Issue 8 2007Leora J. Vegosen Objective To evaluate whether seasonal early environmental exposures might influence later development of autoimmune disease, by assessing distributions of birth dates in groups of patients with idiopathic inflammatory myopathies (IIMs). Methods We assessed birth patterns in groups of patients with juvenile-onset IIM (n = 307) and controls (n = 3,942) who were born between 1970 and 1999, and in groups of patients with adult-onset IIM (n = 668) and controls (n = 6,991) who were born between 1903 and 1982. Birth dates were analyzed as circular data. Seasonal clustering was assessed by the Rayleigh test, and differences between groups by a rank-based uniform scores test. Results The overall birth distributions among patients with juvenile IIM and among patients with adult IIM did not differ significantly from those among juvenile and adult controls, respectively. Some subgroups of patients with juvenile IIM had seasonal birth distributions. Hispanic patients with juvenile-onset IIM had a seasonal birth pattern (mean birth date October 16) significantly different from that of Hispanic controls (P = 0.002), who had a uniform birth distribution, and from that of non-Hispanic patients with juvenile-onset IIM (P < 0.001), who had a mean birth date of May 2. Juvenile dermatomyositis patients with p155 autoantibody had a birth distribution that differed significantly from that of p155 antibody,negative juvenile dermatomyositis patients (P = 0.003). Juvenile IIM patients with the HLA risk factor allele DRB1*0301 had a birth distribution significantly different from those without the allele (P = 0.021). Similar results were observed for juvenile and adult IIM patients with the linked allele DQA1*0501, versus juvenile and adult IIM patients without DQA1*0501, respectively. No significant patterns in birth season were found in other subgroups. Conclusion Birth distributions appear to have stronger seasonality in juvenile than in adult IIM subgroups, suggesting greater influence of perinatal exposures on childhood-onset illness. Seasonal early-life exposures may influence the onset of some autoimmune diseases later in life. [source] Evolution of reproductive seasonality in bearsMAMMAL REVIEW, Issue 1 2007THOMAS J. SPADY ABSTRACT 1Of the eight species of Ursidae, six are currently at risk of extinction and the remainder face significant risks to their future survival. One of the greatest threats to bears is human-imposed environmental alteration (e.g. global warming, chemical pollutants, deforestation). An examination of the reproductive biology and phylogeny of the Ursidae reveals reproductive seasonality as a probable adaptation to adverse environmental conditions. 2Seven of the eight extant species exhibit distinct mating and birth seasons, with the most ancient species evolving facultative seasonality as an adaptation to the increasingly seasonal climate of the Pliocene. The remainder of the extant species evolved during the Pleistocene glaciations, under conditions of severe seasonal food restriction. Under these conditions, an obligate mode of seasonality emerged and persists to the present. 3Knowledge of the natural history of seasonal reproduction in the ursids and how it evolved in response to global climatic change provides a context for understanding the ramifications of current environmental change on the reproduction of these important species. [source] Coat condition of ringtailed lemurs, Lemur catta at Berenty Reserve, Madagascar: I. differences by age, sex, density and tourism, 1996,2006AMERICAN JOURNAL OF PRIMATOLOGY, Issue 3 2009Alison Jolly Abstract An index of coat condition can be a non-invasive tool for tracking health and stress at population level. Coat condition in ringtailed lemurs, Lemur catta, was recorded during September,November birth seasons of 1996, 1997, 1999, and 2001,2006 at Berenty Reserve, Madagascar. Condition was scored on a scale from 0: full, fluffy coat with guard hairs present, to 5: half or more of body hairless. Adult males did not differ overall from adult females. Coats were worse in adults than in 2-year-old subadults; 1-year-old juveniles were intermediate. Mothers and adult males lost coat condition as the season progressed: non-mother females maintained condition. Years 1999,2002 scored better coats than either 1996,1997 or 2003,2006. Lemurs in high population density areas had worse coats than in natural forest, but tourist presence had less effect than density. Monitoring coat condition in an apparently healthy population reveals differences between population segments, and in a forest fragment with limited immigration or emigration it can track progressive changes, correcting impressions of progressive improvement or degradation over time. Above all it gives a baseline for response to climate changes or eventual pathology. Am. J. Primatol. 71:191,198, 2009. © 2008 Wiley-Liss, Inc. [source] Coat condition of ringtailed lemurs, Lemur catta, at Berenty Reserve, Madagascar: II.AMERICAN JOURNAL OF PRIMATOLOGY, Issue 3 2009tail alopecia associated with Leucaena leucocepahala Abstract Fur condition in wild ringtailed lemurs, Lemur catta, was recorded during September,November birth seasons 2001,2006 at Berenty Reserve, Madagascar. Body coat condition was scored on a scale from BS 0: full, smooth coat with guard hairs, to BS5: half or more of back and limbs hairless. Tail condition was scored from TS 0: full, to TS 5: half or more hairless. Where troop core areas included stands of Leucaena leucocephala, alopecia was dramatically more frequent than in similar areas without leucaena, including many animals with score BS5 or TS5, "bald lemur syndrome." Female coats were worse than males,' possibly related to female dominance and access to this preferred food. Tails in non-leucaena-feeding females tend to remain full, even if coats deteriorate, but with leucaena-feeding female tails are highly correlated with coat condition and equally bare. Coat and tail condition in L. catta reflected not only the dietary toxin but individual differences as well as differences between adjacent troops that may result from territorially mediated access to the environment. Leucaena contains the non-protein amino acid mimosine, a known cause of alopecia, wasting, and organ damage in livestock, although the effects are usually reversible. This is the first case of its effect in wildlife. Leucaena is an agroforestry tree introduced throughout the tropics. In high dietary concentrations leucaena might potentially affect any browsing mammal. Am. J. Primatol. 71:199,205, 2009. © 2008 Wiley-Liss, Inc. [source] | ||||||||||